teemperor created this revision.
teemperor added a reviewer: aprantl.
Herald added subscribers: llvm-commits, cfe-commits, hiraditya.
Herald added projects: clang, LLVM.
With DWARF5 it is no longer possible to distinguish normal methods and methods
with `__attribute__((objc_direct))` by just looking at the debug information
as they are both now children of the of the DW_TAG_structure_type that defines
them (before only the `__attribute__((objc_direct))` methods were children).
This means that in LLDB we are no longer able to create a correct Clang AST of
a module by just looking at the debug information. Instead we would
need to call the Objective-C runtime to see which of the methods have a
`__attribute__((objc_direct))` and then add the attribute to our own Clang AST
depending on what the runtime returns. This would mean that we either let the
module AST be dependent on the Objective-C runtime (which doesn't
seem right) or we retroactively add the missing attribute to the imported AST
in our expressions.
A third option is to annotate methods with `__attribute__((objc_direct))` as
`DW_AT_APPLE_objc_direct` which is what this patch implements. This way
LLDB doesn't have to call the runtime for any `__attribute__((objc_direct))`
method and the AST in our module will already be correct when we create it.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D71201
Files:
clang/lib/CodeGen/CGDebugInfo.cpp
clang/test/CodeGenObjC/debug-info-direct-method.m
llvm/include/llvm/BinaryFormat/Dwarf.def
llvm/include/llvm/IR/DebugInfoFlags.def
llvm/include/llvm/IR/DebugInfoMetadata.h
llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
llvm/test/DebugInfo/X86/objc_direct.ll
Index: llvm/test/DebugInfo/X86/objc_direct.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/X86/objc_direct.ll
@@ -0,0 +1,122 @@
+; RUN: llc < %s -filetype=obj -o %t
+; RUN: llvm-dwarfdump -v %t | FileCheck %s
+
+; Source code to regenerate:
+; __attribute__((objc_root_class))
+; @interface Root
+; - (int)direct_method __attribute__((objc_direct));
+; @end
+;
+; @implementation Root
+; - (int)direct_method __attribute__((objc_direct)) {
+; return 42;
+; }
+; @end
+;
+; clang -O0 -g -gdwarf-5 direct.m -c
+
+; CHECK: DW_TAG_subprogram [3]
+; CHECK: DW_AT_APPLE_objc_direct
+; CHECK-SAME: DW_FORM_flag_present
+; CHECK: DW_TAG_formal_parameter [4]
+
+; ModuleID = 'direct.bc'
+source_filename = "direct.m"
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.15.0"
+
+%0 = type opaque
+%struct._objc_cache = type opaque
+%struct._class_t = type { %struct._class_t*, %struct._class_t*, %struct._objc_cache*, i8* (i8*, i8*)**, %struct._class_ro_t* }
+%struct._class_ro_t = type { i32, i32, i32, i8*, i8*, %struct.__method_list_t*, %struct._objc_protocol_list*, %struct._ivar_list_t*, i8*, %struct._prop_list_t* }
+%struct.__method_list_t = type { i32, i32, [0 x %struct._objc_method] }
+%struct._objc_method = type { i8*, i8*, i8* }
+%struct._objc_protocol_list = type { i64, [0 x %struct._protocol_t*] }
+%struct._protocol_t = type { i8*, i8*, %struct._objc_protocol_list*, %struct.__method_list_t*, %struct.__method_list_t*, %struct.__method_list_t*, %struct.__method_list_t*, %struct._prop_list_t*, i32, i32, i8**, i8*, %struct._prop_list_t* }
+%struct._ivar_list_t = type { i32, i32, [0 x %struct._ivar_t] }
+%struct._ivar_t = type { i64*, i8*, i8*, i32, i32 }
+%struct._prop_list_t = type { i32, i32, [0 x %struct._prop_t] }
+%struct._prop_t = type { i8*, i8* }
+
+@_objc_empty_cache = external global %struct._objc_cache
+@"OBJC_CLASS_$_Root" = global %struct._class_t { %struct._class_t* @"OBJC_METACLASS_$_Root", %struct._class_t* null, %struct._objc_cache* @_objc_empty_cache, i8* (i8*, i8*)** null, %struct._class_ro_t* @"_OBJC_CLASS_RO_$_Root" }, section "__DATA, __objc_data", align 8
+@"OBJC_METACLASS_$_Root" = global %struct._class_t { %struct._class_t* @"OBJC_METACLASS_$_Root", %struct._class_t* @"OBJC_CLASS_$_Root", %struct._objc_cache* @_objc_empty_cache, i8* (i8*, i8*)** null, %struct._class_ro_t* @"_OBJC_METACLASS_RO_$_Root" }, section "__DATA, __objc_data", align 8
+@OBJC_CLASS_NAME_ = private unnamed_addr constant [5 x i8] c"Root\00", section "__TEXT,__objc_classname,cstring_literals", align 1
+@"_OBJC_METACLASS_RO_$_Root" = internal global %struct._class_ro_t { i32 3, i32 40, i32 40, i8* null, i8* getelementptr inbounds ([5 x i8], [5 x i8]* @OBJC_CLASS_NAME_, i32 0, i32 0), %struct.__method_list_t* null, %struct._objc_protocol_list* null, %struct._ivar_list_t* null, i8* null, %struct._prop_list_t* null }, section "__DATA, __objc_const", align 8
+@"_OBJC_CLASS_RO_$_Root" = internal global %struct._class_ro_t { i32 2, i32 0, i32 0, i8* null, i8* getelementptr inbounds ([5 x i8], [5 x i8]* @OBJC_CLASS_NAME_, i32 0, i32 0), %struct.__method_list_t* null, %struct._objc_protocol_list* null, %struct._ivar_list_t* null, i8* null, %struct._prop_list_t* null }, section "__DATA, __objc_const", align 8
+@"OBJC_LABEL_CLASS_$" = internal global [1 x i8*] [i8* bitcast (%struct._class_t* @"OBJC_CLASS_$_Root" to i8*)], section "__DATA,__objc_classlist,regular,no_dead_strip", align 8
+@llvm.compiler.used = appending global [2 x i8*] [i8* getelementptr inbounds ([5 x i8], [5 x i8]* @OBJC_CLASS_NAME_, i32 0, i32 0), i8* bitcast ([1 x i8*]* @"OBJC_LABEL_CLASS_$" to i8*)], section "llvm.metadata"
+; Function Attrs: noinline optnone ssp uwtable
+define hidden i32 @"\01-[Root direct_method]"(%0* %self, i8* %_cmd) #0 !dbg !24 {
+entry:
+ %retval = alloca i32, align 4
+ %self.addr = alloca %0*, align 8
+ %_cmd.addr = alloca i8*, align 8
+ store %0* %self, %0** %self.addr, align 8
+ call void @llvm.dbg.declare(metadata %0** %self.addr, metadata !25, metadata !DIExpression()), !dbg !27
+ store i8* %_cmd, i8** %_cmd.addr, align 8
+ call void @llvm.dbg.declare(metadata i8** %_cmd.addr, metadata !28, metadata !DIExpression()), !dbg !27
+ %0 = load %0*, %0** %self.addr, align 8, !dbg !30
+ %1 = icmp eq %0* %0, null, !dbg !30
+ br i1 %1, label %objc_direct_method.self_is_nil, label %objc_direct_method.cont, !dbg !30, !prof !31
+
+objc_direct_method.self_is_nil: ; preds = %entry
+ %2 = bitcast i32* %retval to i8*, !dbg !30
+ call void @llvm.memset.p0i8.i64(i8* align 4 %2, i8 0, i64 4, i1 false), !dbg !30
+ br label %return, !dbg !30
+
+objc_direct_method.cont: ; preds = %entry
+ store i32 42, i32* %retval, align 4, !dbg !32
+ br label %return, !dbg !32
+
+return: ; preds = %objc_direct_method.cont, %objc_direct_method.self_is_nil
+ %3 = load i32, i32* %retval, align 4, !dbg !33
+ ret i32 %3, !dbg !33
+}
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #2
+
+attributes #0 = { noinline optnone ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable willreturn }
+attributes #2 = { argmemonly nounwind willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14, !15, !16, !17, !18, !19, !20, !21, !22}
+!llvm.ident = !{!23}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_ObjC, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project d6b2f33e2b6338d24cf756ba220939aecc81210d)", isOptimized: false, runtimeVersion: 2, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+!1 = !DIFile(filename: "direct.m", directory: "/", checksumkind: CSK_MD5, checksum: "6b49fad130344b0011fc0eef65949390")
+!2 = !{}
+!3 = !{!4}
+!4 = !DICompositeType(tag: DW_TAG_structure_type, name: "Root", scope: !1, file: !1, line: 2, flags: DIFlagObjcClassComplete, elements: !5, runtimeLang: DW_LANG_ObjC)
+!5 = !{!6}
+!6 = !DISubprogram(name: "-[Root direct_method]", scope: !4, file: !1, line: 7, type: !7, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagObjCDirect, retainedNodes: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !11}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !4, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
+!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "SEL", file: !1, baseType: !12, flags: DIFlagArtificial)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
+!13 = !DICompositeType(tag: DW_TAG_structure_type, name: "objc_selector", file: !1, flags: DIFlagFwdDecl)
+!14 = !{i32 1, !"Objective-C Version", i32 2}
+!15 = !{i32 1, !"Objective-C Image Info Version", i32 0}
+!16 = !{i32 1, !"Objective-C Image Info Section", !"__DATA,__objc_imageinfo,regular,no_dead_strip"}
+!17 = !{i32 4, !"Objective-C Garbage Collection", i32 0}
+!18 = !{i32 1, !"Objective-C Class Properties", i32 64}
+!19 = !{i32 7, !"Dwarf Version", i32 5}
+!20 = !{i32 2, !"Debug Info Version", i32 3}
+!21 = !{i32 1, !"wchar_size", i32 4}
+!22 = !{i32 7, !"PIC Level", i32 2}
+!23 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project d6b2f33e2b6338d24cf756ba220939aecc81210d)"}
+!24 = distinct !DISubprogram(name: "-[Root direct_method]", scope: !1, file: !1, line: 7, type: !7, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, declaration: !6, retainedNodes: !2)
+!25 = !DILocalVariable(name: "self", arg: 1, scope: !24, type: !26, flags: DIFlagArtificial | DIFlagObjectPointer)
+!26 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !4, size: 64)
+!27 = !DILocation(line: 0, scope: !24)
+!28 = !DILocalVariable(name: "_cmd", arg: 2, scope: !24, type: !29, flags: DIFlagArtificial)
+!29 = !DIDerivedType(tag: DW_TAG_typedef, name: "SEL", file: !1, baseType: !12)
+!30 = !DILocation(line: 7, column: 1, scope: !24)
+!31 = !{!"branch_weights", i32 1, i32 1048576}
+!32 = !DILocation(line: 8, column: 3, scope: !24)
+!33 = !DILocation(line: 9, column: 1, scope: !24)
Index: llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1233,6 +1233,9 @@
Language == dwarf::DW_LANG_ObjC))
addFlag(SPDie, dwarf::DW_AT_prototyped);
+ if (SP->isObjCDirect())
+ addFlag(SPDie, dwarf::DW_AT_APPLE_objc_direct);
+
unsigned CC = 0;
DITypeRefArray Args;
if (const DISubroutineType *SPTy = SP->getType()) {
Index: llvm/include/llvm/IR/DebugInfoMetadata.h
===================================================================
--- llvm/include/llvm/IR/DebugInfoMetadata.h
+++ llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -1758,6 +1758,7 @@
bool isPure() const { return getSPFlags() & SPFlagPure; }
bool isElemental() const { return getSPFlags() & SPFlagElemental; }
bool isRecursive() const { return getSPFlags() & SPFlagRecursive; }
+ bool isObjCDirect() const { return getSPFlags() & SPFlagObjCDirect; }
/// Check if this is deleted member function.
///
Index: llvm/include/llvm/IR/DebugInfoFlags.def
===================================================================
--- llvm/include/llvm/IR/DebugInfoFlags.def
+++ llvm/include/llvm/IR/DebugInfoFlags.def
@@ -90,11 +90,12 @@
// May also utilize this Flag in future, when adding support
// for defaulted functions
HANDLE_DISP_FLAG((1u << 9), Deleted)
+HANDLE_DISP_FLAG((1u << 10), ObjCDirect)
#ifdef DISP_FLAG_LARGEST_NEEDED
// Intended to be used with ADT/BitmaskEnum.h.
// NOTE: Always must be equal to largest flag, check this when adding new flags.
-HANDLE_DISP_FLAG((1 << 9), Largest)
+HANDLE_DISP_FLAG((1 << 10), Largest)
#undef DISP_FLAG_LARGEST_NEEDED
#endif
Index: llvm/include/llvm/BinaryFormat/Dwarf.def
===================================================================
--- llvm/include/llvm/BinaryFormat/Dwarf.def
+++ llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -421,6 +421,7 @@
HANDLE_DW_AT(0x3feb, APPLE_property_attribute, 0, APPLE)
HANDLE_DW_AT(0x3fec, APPLE_objc_complete_type, 0, APPLE)
HANDLE_DW_AT(0x3fed, APPLE_property, 0, APPLE)
+HANDLE_DW_AT(0x3fee, APPLE_objc_direct, 0, APPLE)
// Attribute form encodings.
HANDLE_DW_FORM(0x01, addr, 2, DWARF)
Index: clang/test/CodeGenObjC/debug-info-direct-method.m
===================================================================
--- clang/test/CodeGenObjC/debug-info-direct-method.m
+++ clang/test/CodeGenObjC/debug-info-direct-method.m
@@ -1,12 +1,17 @@
// RUN: %clang_cc1 -dwarf-version=5 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - | FileCheck %s
// RUN: %clang_cc1 -dwarf-version=4 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - | FileCheck %s
+// RUN: %clang_cc1 -dwarf-version=5 -emit-llvm -debug-info-kind=limited -w -triple x86_64-apple-darwin10 %s -o - -DDISABLE_DIRECT | FileCheck --check-prefix=CHECK-DISABLED %s
__attribute__((objc_root_class))
@interface Root
@end
@implementation Root
-- (int)getInt __attribute__((objc_direct)) {
+- (int)getInt
+#ifndef DISABLE_DIRECT
+ __attribute__((objc_direct))
+#endif
+{
return 42;
}
@end
@@ -19,3 +24,6 @@
// CHECK-SAME: runtimeLang: DW_LANG_ObjC)
// CHECK: ![[MEMBERS]] = !{![[GETTER:[0-9]+]]}
// CHECK: ![[GETTER]] = !DISubprogram(name: "-[Root getInt]",
+// CHECK-SAME: spFlags: DISPFlagObjCDirect
+
+// CHECK-DISABLED-NOT: DISPFlagObjCDirect
Index: clang/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- clang/lib/CodeGen/CGDebugInfo.cpp
+++ clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3494,6 +3494,9 @@
if (CGM.getCodeGenOpts().DwarfVersion < 5 && !OMD->isDirectMethod())
return nullptr;
+ if (OMD->isDirectMethod())
+ SPFlags |= llvm::DISubprogram::SPFlagObjCDirect;
+
// Starting with DWARF V5 method declarations are emitted as children of
// the interface type.
auto *ID = dyn_cast_or_null<ObjCInterfaceDecl>(D->getDeclContext());
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